Lock-stitch sewing-machine.



T. G. PLANT; LOCK 'STITGH SEWING MACHINE. APPLIOATIORI'ILED-APR.15/1908. RENEWED APR. 14, 1909.

I 940,726. Patented Nov. 23, 1909.

3 SHEETS-SHEET 1.

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T. G. PLANT. LOCK STITCH SEWING MACHINE. APPLIUATION'PILED APR.15, 1908. RENEWBD APR. 14, 1909.

Patented Nov. 23,1909.

3 SHEETS-SHEET 2.

I m w M 'fl/Wm Arr)? T. G 1 LANT.. v I LOOK STITCH SEWING MACHINE. APPLICATION FILED APR. 15, 1908. RENEWED APB. 14,1909.

Patented Nov.'23,-1.9'09, a B HEETS.8H

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To all iohom may concern:

. tion withthe accompanyingdrawings, is a relates to shoe Sewing machines of that gen -n1ent inv Lock-Stitch taking only of a movement toward and roni needle thread. .In such N T D STATES PATEN OFFICE Tnomese. PLANT, or BoSToN, MASSACHUSETTS.

, Application fileu April 151908,

Be itk'no'wn that I, THOMAS G. PLANT, a citizen of .the United States, "residing at Boston, 'in the county of Suffolk and State of Massachusetts, have invented an Improve- Sewing-Machines, of which the following description, in connecspecification, likecharacters on the drawings representing like' partsp I The invention to be hereinafter described eral type using ashuttle and a'nfeedle thread which are interlooped to 'form lock-stitches: In setting the stitchin such type of machine, how-ever, difficulty has been experiencedin Securing a uniform location of the interlooped or interlocked portionsof the shuttle and needlelt-hrea'ds with respect to, the surface of the work. The importance of-securing a uniform location of-the stitch lock has bee'n'r'ecognized and understood hereto-- foreQand attempts have'been made in "lock stitch sewing machinesto secure uniformity" in this respect, various expedients being devised With such end in view. As well understood by those skilled in theart, it is desirable. that the bobbin carrying the shuttle thread be disposed eccentricallyfin the shuts; tle with the shuttle thr'e'a'd "delivery eye ar the stitch making point-as the shuttle is oscillatedto pick up andg-c'ast the loop of type oi niachine, however, afterthe stiteh'has been 'set by a pull upon the needle thread, andthe stitch setting-means has given up slack to the needle thread in order that the thread finger might deflect the thread and the looper might'properly the needle thread about the needle forthe next stitch, the oscillation of the shuttlcback to its initial p'osition'has caused'the shuttle to pull'thread froni tlie' shuttle bobbin for the next stitch, such pull being enerted by the. shuttle thread on the thread-lock now. held in position by a'c'o'mparalirely slack needle thread. The effect of this has been to "pull up the thread lock more or'less' anddn a line of stitching to present irregularities.inthc location thereof, In the attempts heretofrire made to overcome this ob iection',"'t he desirablecharacteristics of the machine have been largely sacrificed, as by additional mechanism to give bodily movements to the shuttle and its thread mass l respect to the, surface j IJocIQSTI H. EWING-MACHINE) I toward and from the work, orby a con-'- ccntric mounting of the shuttle, its 'bobbin case, and a delivery eye centrally disposed with relation to the shuttle combined with a shuttle,thread-lock or take-up,all of which introduce objections Well understood by those skilled in the art. H

The present invention is designed as an improvement on these prior attempts whereby the desirable features of the ma chine as hereinbefore noted are retained, and means are provided and given charac teristic movements whereby not only is the stitch set-by a pull on the needle thread, but such pull is exerted on a taut shuttlethread; and such stitch setting pull. on the needle thread draws'f-rom ,the shuttle the entire -amountfl0f shuttle thread needed forthe Stitch, theefiect of such operation being that the interlooped portions of shuttle and needle: threads are uniformly located with. of the work, and since I pe fi fi of Letters wn- Patented Nov. 23, 1909.] seriarmf izmsa 'Renewed April li, 1909. Serial m nages.

the entire amount of shuttle thread is drawn from the shuttle by the needle thread as'it" sets the stitch, the stitch loopor look is not thereafter disturbed by any pull by the shuttle thread, all as will hereinafter be more fullydescribed and then definitely pointedout in the claims.

The invention is herein illustrated and described as embodied in a machine of the.

general type presented by theFrench and Meyer patent, No., 473,870, dated April 26,

full disclosure of characteristic structure in such machine. f I i In the drawings F igure 1: in side elevation representssufiicient of the machine to the parts thereof; Fig,'2' 1s a view similar to 1, with the parts in a somewhatd if- 7 position, and certain other parts, omitted for clearness of llustratlong Fig. S5

ferent 1s a detail front view illustrating the positionof the shuttle, in accordance w th the present lnvcnt on, as just completing its 1892, to which reference may be had for a,

make clear the invention and its relation to movement in the direction of-nthearrowto.

cast the loop ofneedle thread and prioifito setting the stitch;

-Fig. ,4 alike detail View showing the shuttle as moving in-jhe direction ofthe arrow to. carryth e nose of the shuttle to initial positionfor entering the next loop of needle thread, and the stitch as having just been set; Fig. 5 is a similar detail view showing the shuttle as having llU completed its movement to initial position and about to. start on its loop taking movement in the direction of the arrow, the needle thread at such time being manipu-. lated by-thethread finger and looper to carry the thread about the needle.

presser-foot 0 may be-of the general char.

acter of the like parts in the patent to French and Meyer, 473,870, hereinbefore mentioned, except inso far as said .partsand thelr operative relation are changed, as will be hereinafter fully set forth.-

The tension device t, the ma-in'take-up. arm g carrymgthe roll 9, mounted on the:

stud g, and operated from the main shaft A; the auxiliary take-up g*,-'mounted on the stud 7, its spring 8, and roll 5; the stop 34; the thread clamp it, the roller .9 mounted on the stud g and the thread measure g, its.

mounting f and connections, are or may be substantially as the like parts and associated devices in the said French 'andMeyer patent.

Referring to Figs. 3, 1 and 5, as representing the characteristics of applicants inven-,

tion the work is fed in the direction of the arrow, Fig. 5, and a looper 25 thread finger a", needle a presser-foot e and their operating connections are employed, as indicatedin the French and Meyer patent to which reference may be had.

- The shuttle 10 has the usual nose 11, and carries an eccentrically mounted bobbin case 13, provided with a shuttle thread delivery eye 14 projecting therefrom, and guided by a recess in the under face of the arm D", so

- that the bobbin case is restrained from turning about its axis.

The center of the shuttle about which it oscillates is designated by 20, and 21 indicates the center of the bobbin or bobbin case, so that as the shuttle is oscillated to engage and cast the needle loop and then back to initial position, the center21 of the bobbin or bobbin case moves in the arc of acircle from the position 21 of Fig. 5, to the position 21, Figs. 3 and 4;, the vertical movement of the center 21 ofthe bobbin or bobbin case, and consequently the delivery eye 14, heingthe same.

In oscillating the shuttle contra-clockwise from the position indicated in Fig. 5 to that indicated in Fig. 3 to engage and cast the needle loop, and in returning it to its initial position, it will be noted that the center of the bobbin case moves through the arc of a circle indicated by the radial lines Z, vW,

but that in such loop casting movement thevertical rise of the center 21 and consequently of the delivery eye 14 is greater than the vertical movement of the center 21 and delivery eye ll, as the-shuttle moves from loop casting position, Figs. 3 and 4, backto initial position, of Fig. 5, the difference of such vertical movement being indicated by the diflerenee in the vertical side of the triangle 20, 21 and 22 of Fig. 5, and 20, 21, and 23 of Figs. 3 and 4. This characteristic movement of the shuttle results from im-.

parting thereto'an oscillating movement in the arc of a circle to substantially the same extent on each side of a. line connecting the stitch makin point and center of oscillation of thes iut'tle, as indicated in Figs. 3, 4 and In other words, as the shuttle'is oscillated to engage and cast the needle loop which has been drawn up through the work by the needle, as in Fig. 3, and during the stitch setting movement, as in Fig. :1, the

shuttle has, carried the bobbin or bobbin case and consequently the delivery eye to a position at least as far from the stitch makm point as it does when the said shuttle is returned to itsinitial position as in Fig. 5. The effect of this is that the interlock of .the needle and shuttle threads is formed, as in Fig. 3, with the shuttle thread 8 taut,-and.as the needle thread is manipulated by the take-up to 'set the stitch, Figs. 1 and .4, the needle thread pulls from the shuttle all .the shuttle thread needed for the stitch being formed, so that as the shuttle is oscillated hack to-initial position, as indicated in Fig. 5, preparatory to engagin a needle loop, the said shuttle does not pul fromitself any shuttle thread, and consequently does not pull upon the thread lock' 19.

As willbe obvious to one skilled in the art, the distance between the center 21 and the stitch forming point will .be substantially the same whether the shuttle is in its loop casting position or has returned to its initial position, and it will be likewise apparent that this characteristic relation of parts results from imparting to the shuttle oscillatory movements to substantially equal extent to each side of a line connecting the stitch making point and shuttle center, thus, instead of drawing the shuttle thread from the bobbin by a pull of such thread against a set stitch, the take-up is caused to not only set the stitch by a pull upon the needle thread, but also to draw from the shuttle the entire amount of thread required for the stitch and set the stitch against a taut shuttle thread. i Various modifications in the means employed may suggest themselves to those familiarwith machines of this type, but providing means, such as the rack D and pinion D to, give to the shuttle the characteri'stic movements with relation to the action ofthetake-up or. other stitch setting means, has been found practically. successful and advantageous What is claimed is: 1. In a shoe-sewing.machine for making lock stitches, the combination of stitch forming mechanism, including a shuttle and needle, means for oscillating the shuttle to pass, the shuttle threadlthrough the loop of needle thread and by said movement draw the shuttle thread taut, means'for pulling upon the needle-thread to set thestitch against the taut shuttle thread and simultaneouslyto draw from the shuttle the entire amount of shuttle thread to form the stitch, said oscillating means returning the shuttle to its initial. position with the shuttle thread slack-.'

2. In a shoe-sewing machine for making lock-stitches, the combination of stitch form- -'ing mechanism, including 'a shuttle and lock-stitches, the combination of stitch form- I ing mechanism including a shuttle and needle, said shuttle having a bobbin receivmg recess eccentrically d sposed therein,

means to oscillate the shuttle to 'pass the v shuttle thread 'throughthe needle loop and raise the shuttle thread a maximum dis? tance from the work, means to pull upon the needle thread to set the stitch'and draw fromthe shuttlethe entire amount of shuttle illl'(*i1(l:t()-f01'll1 the stitch, the return oscilla-\ I tionfof the shuttle carrying the shuttle thread a less distance from the work than the loop .casting oscillation.

2h. In'a shoe-sewing machine for making lock-stitches, the combination of stitch forming mechanism, including a shuttle, said shuttle having a bobbin receiving recess eecentrically disposed therein, a bobbin case having a shuttle thread delivery eye, means to restrain rotative movement of the bobbin case upon its axis, means to oscillate the shuttle to carry the shuttle thread through the loop of needle thread and continue said movement to raise the shuttle thread a maximum distance from the-work, and means to pull upon the needle thread toset the stitch and draw from the shuttle the entire amount of shuttle thread to form the stitch the return oscillation of the shuttle carrying the shuttle thread no greater distance from the work than the loop engaging and casting oscillation.

In testimony whereof, I" have signed my G5 name to this specification, in the presence of two subscribing witnesses.

THOMAS G. PLANT.

Witnesses:

-AMELIA M. Ross,

MARION .F. KIMBALL. 

